Supporting different numerology configurations

ABSTRACT

In wireless communication systems that support 5G or NR protocols, subframes used for communication may have different numerology options. Numerology options may refer to the characteristics of the subframe such as a tone spacing within each symbol of the subframe, a symbol duration for each symbol of the subframe, a number of symbols in the subframe, etc. A subframe may include a control channel (e.g., the PDCCH) and a data channel (e.g., the PDSCH). In an aspect, the control channel and the data channel within the subframe may have different numerologies. As such, a need exists to signal the numerology of the subframe to users and to determine whether and how to multiplex the control channel and the data channel into the subframe.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Application Ser.No. 62/379,697, entitled “SUPPORTING DIFFERENT NUMEROLOGYCONFIGURATIONS” and filed on Aug. 25, 2016, which is expresslyincorporated by reference herein in its entirety.

BACKGROUND Field

The present disclosure relates generally to communication systems, andmore particularly, to a network supporting different numerologyconfigurations and employing transmission gaps.

Background

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources. Examples of suchmultiple-access technologies include code division multiple access(CDMA) systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example telecommunication standardis Long Term Evolution (LTE). LTE is a set of enhancements to theUniversal Mobile Telecommunications System (UMTS) mobile standardpromulgated by Third Generation Partnership Project (3GPP). LTE isdesigned to support mobile broadband access through improved spectralefficiency, lowered costs, and improved services using OFDMA on thedownlink, SC-FDMA on the uplink, and multiple-input multiple-output(MIMO) antenna technology. However, as the demand for mobile broadbandaccess continues to increase, there exists a need for furtherimprovements in LTE and other communication technologies. Theseimprovements may also be applicable to other multi-access technologiesand the telecommunication standards that employ these technologies.

5G (or new radio (NR)) systems may support different numerology optionswithin a subframe. New designs and signaling are needed to support thenumerology options.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

Networks that support 5G communication may support different numerologyoptions across and even within a subframe. For example, two differentsubframes may have different tone spacing. Base stations and userequipments, however, may have existing assumptions about the type oftone spacing within each symbol. As such, if the tone spacing is tochange, signaling is needed to support the changes in tone spacing andother numerology changes. As further discussed below, base stations mayutilize a first type of subframe with a known numerology configurationto transmit information to user equipment indicating the numerologyconfiguration to be used for subsequent subframes. When the userequipment receives the first type of subframes, the user equipment willdecode the subframe and become aware of the numerology configurations tobe used for future communications with the base station.

In an aspect of the disclosure, a method, a computer-readable medium,and an apparatus are provided. In an aspect, an apparatus within thenetwork may be configured to determine a numerology configuration to beused for communication with user equipment. The apparatus may determineone or more fallback subframes and communicate with the user equipmentwithin the one or more fallback subframes based on the determinednumerology configuration.

Another aspect of the disclosure provides for an apparatus for wirelesscommunication. The apparatus may include means for determining anumerology configuration to be used for communicating with a UE, meansfor determining one or more fallback subframes, and means forcommunicating with the UE within the one or more fallback subframesbased on the determined numerology configuration.

Another aspect of the disclosure provides for a computer-readable mediumstoring computer executable code. The computer-readable medium includescode to determine a numerology configuration to be used forcommunicating with a UE, to determine one or more fallback subframes,and to communicate with the UE within the one or more fallback subframesbased on the determined numerology configuration.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus are provided. The apparatus may determine anominal numerology and a numerology configuration to be used for asubframe. The numerology configuration may include a first tone spacingin the subframe for a control channel and a second tone spacing in thesubframe for a data channel. The apparatus may transmit the subframe toa user equipment.

Another aspect of the disclosure provides a method of wirelesscommunication by a base station. The method includes determining anominal numerology and a numerology configuration to be used for asubframe. The numerology configuration may include a first tone spacingin the subframe for a control channel and a second tone spacing in thesubframe for a data channel. The method includes transmitting thesubframe to a UE. In an aspect, the first tone spacing may be the sameas the second tone spacing. In another aspect, the first tone spacingmay be different from the second tone spacing. In another aspect, thefirst tone spacing may be an integer multiple of the second tonespacing. In another aspect, the first tone spacing may be a firstinteger multiple of a tone spacing of the nominal numerology and thesecond tone spacing may be a second integer multiple of the tone spacingof the nominal numerology. In another configuration, the method mayinclude determining whether to TDM the control channel with the datachannel into adjacent symbols based on the determined numerologyconfiguration of the subframe. In another aspect, the base stationdetermines not to TDM the control channel with the data channel intoadjacent symbols if the adjacent symbols have different tone spacingsand the transmission of the two adjacent symbols will overlap withsymbol boundaries corresponding to the nominal numerology. In anotheraspect, the subframe may include one or more gap symbols between thetransmission of the control channel and the data channel. In anotheraspect, the one or more gap symbols may include reference signals or L1control signals. In another aspect, the one or more gap symbols may usea same tone spacing as the control channel or may use a different tonespacing from the control channel. In another aspect, the first tonespacing of the control channel may be an integer multiple of the secondtone spacing of the data channel, and the one or more gap symbols mayhave the first tone spacing.

Another aspect of the disclosure provides for an apparatus. Theapparatus includes means for determining one or more fallback subframesand determine a numerology configuration to be used for communicationwith a base station within the one or more fallback subframes and meansfor communicating within the one or more fallback subframes based on thedetermined numerology configuration.

Another aspect of the disclosure provides for an apparatus for wirelesscommunication. The apparatus includes a memory and at least oneprocessor. The at least one processor may be coupled to the memory andconfigured to determine one or more fallback subframes and determine anumerology configuration to be used for communication with a basestation within the one or more fallback subframes and to communicatewithin the one or more fallback subframes based on the determinednumerology configuration.

Another aspect of the disclosure provides for a computer-readablemedium. The computer-readable medium may include computer executablecode, including code to determine one or more fallback subframes anddetermine a numerology configuration to be used for communication with abase station within the one or more fallback subframes and tocommunicate within the one or more fallback subframes based on thedetermined numerology configuration.

In another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus are provided. The apparatus may determine oneor more fallback subframes and determine a numerology configuration tobe used for communication with a base station within the one or morefallback subframes. The apparatus may communicate within the one or morefallback subframes based on the determined numerology configuration.

Another aspect of the disclosure provides an apparatus for wirelesscommunication. The apparatus may include means for determining one ormore fallback subframes, means for determining a numerologyconfiguration to be used for communication with a base station withinthe one or more fallback subframes, and means for communicating withinthe one or more fallback subframes based on the determined numerologyconfiguration.

Another aspect of the disclosure provides a computer-readable mediumstoring computer executable code. The computer-readable medium includescode to determine one or more fallback subframes, to determine anumerology configuration to be used for communication with a basestation within the one or more fallback subframes, and to communicatewithin the one or more fallback subframes based on the determinednumerology configuration.

In yet another aspect of the disclosure, a method, a computer-readablemedium, and an apparatus are provided. The apparatus may receive from abase station a subframe associated with a numerology configuration. Thenumerology configuration may be associated with a first tone spacing inthe subframe for a control channel and a second tone spacing in thesubframe for a data channel. The apparatus may decode the receivedsubframe based on the numerology configuration.

Another aspect of the disclosure provides for a method of wirelesscommunication by a UE. The method may include receiving from a basestation a subframe associated with a numerology configuration, in whichthe numerology configuration is associated with a first tone spacing inthe subframe for a control channel and a second tone spacing in thesubframe for a data channel, and decoding the received subframe based onthe numerology configuration. In an aspect, the first tone spacing maybe the same as the second tone spacing. In another aspect, the firsttone spacing may be different from the second tone spacing. In anotheraspect, the first tone spacing may be an integer multiple of the secondtone spacing. In another aspect, the first tone spacing may be a firstinteger multiple of a tone spacing of a nominal numerology and thesecond tone spacing may be a second integer multiple of the tone spacingof a nominal numerology. In another aspect, the subframe may include oneor more gap symbols between the transmission of the control channel andthe data channel. In another aspect, the one or more gap symbols mayinclude reference signals or L control signals. In another aspect, theone or more gap symbols may use a same tone spacing as the controlchannel or may use a different tone spacing from the control channel. Inanother aspect, a first tone spacing of the control channel may be aninteger multiple of a second tone spacing of the data channel, and theone or more gap symbols may have the first tone spacing.

Another aspect of the disclosure provides for an apparatus for wirelesscommunication. The apparatus may include means for receiving from a basestation a subframe associated with a numerology configuration. Thenumerology configuration may be associated with a first tone spacing inthe subframe for a control channel and a second tone spacing in thesubframe for a data channel. The apparatus may include means fordecoding the received subframe based on the numerology configuration.

Another aspect of the disclosure provides for an apparatus for wirelesscommunication. The apparatus may include a memory and at least oneprocessor coupled to the memory. The at least one processor may beconfigured to receive from a base station a subframe associated with anumerology configuration. The numerology configuration may be associatedwith a first tone spacing in the subframe for a control channel and asecond tone spacing in the subframe for a data channel. The at least oneprocessor may be configured to decode the received subframe based on thenumerology configuration.

Another aspect of the disclosure provides for a computer-readablemedium. The computer readable medium may store computer executable code,including code to receive from a base station a subframe associated witha numerology configuration. The numerology configuration may beassociated with a first tone spacing in the subframe for a controlchannel and a second tone spacing in the subframe for a data channel.The computer-readable medium may also include code to decode thereceived subframe based on the numerology configuration.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless communicationssystem and an access network.

FIGS. 2A, 2B, 2C, and 2D are diagrams illustrating LTE examples of a DLframe structure, DL channels within the DL frame structure, an UL framestructure, and UL channels within the UL frame structure, respectively.

FIG. 3 is a diagram illustrating an example of an evolved Node B (eNB)and user equipment (UE) in an access network.

FIG. 4 is a diagram of a method for indicating a numerologyconfiguration.

FIG. 5 is a diagram of a method for supporting different numerologyconfigurations for data and control channels.

FIGS. 6A-D illustrate additional uses of gap symbols (or transmissiongaps) within a subframe.

FIG. 7 is a flowchart of a method of wireless communication.

FIG. 8 is a flowchart of a method of wireless communication.

FIG. 9 is a flowchart of a method of wireless communication.

FIG. 10 is a flowchart of a method of wireless communication.

FIG. 11 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an exemplary apparatus.

FIG. 12 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 13 is a conceptual data flow diagram illustrating the data flowbetween different means/components in an exemplary apparatus.

FIG. 14 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawings by various blocks, components, circuits,processes, algorithms, etc. (collectively referred to as “elements”).These elements may be implemented using electronic hardware, computersoftware, or any combination thereof. Whether such elements areimplemented as hardware or software depends upon the particularapplication and design constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented as a “processing system” thatincludes one or more processors. Examples of processors includemicroprocessors, microcontrollers, graphics processing units (GPUs),central processing units (CPUs), application processors, digital signalprocessors (DSPs), reduced instruction set computing (RISC) processors,systems on a chip (SoC), baseband processors, field programmable gatearrays (FPGAs), programmable logic devices (PLDs), state machines, gatedlogic, discrete hardware circuits, and other suitable hardwareconfigured to perform the various functionality described throughoutthis disclosure. One or more processors in the processing system mayexecute software. Software shall be construed broadly to meaninstructions, instruction sets, code, code segments, program code,programs, subprograms, software components, applications, softwareapplications, software packages, routines, subroutines, objects,executables, threads of execution, procedures, functions, etc., whetherreferred to as software, firmware, middleware, microcode, hardwaredescription language, or otherwise.

Accordingly, in one or more example embodiments, the functions describedmay be implemented in hardware, software, or any combination thereof. Ifimplemented in software, the functions may be stored on or encoded asone or more instructions or code on a computer-readable medium.Computer-readable media includes computer storage media. Storage mediamay be any available media that can be accessed by a computer. By way ofexample, and not limitation, such computer-readable media can comprise arandom-access memory (RAM), a read-only memory (ROM), an electricallyerasable programmable ROM (EEPROM), optical disk storage, magnetic diskstorage, other magnetic storage devices, combinations of theaforementioned types of computer-readable media, or any other mediumthat can be used to store computer executable code in the form ofinstructions or data structures that can be accessed by a computer.

FIG. 1 is a diagram illustrating an example of a wireless communicationssystem and an access network 100. The wireless communications system(also referred to as a wireless wide area network (WWAN)) includes basestations 102, UEs 104, and an Evolved Packet Core (EPC) 160. The basestations 102 may include macro cells (high power cellular base station)and/or small cells (low power cellular base station). The macro cellsinclude eNBs. The small cells include femtocells, picocells, andmicrocells.

The base stations 102 (collectively referred to as Evolved UniversalMobile Telecommunications System (UMTS) Terrestrial Radio Access Network(E-UTRAN)) interface with the EPC 160 through backhaul links 132 (e.g.,S1 interface). In addition to other functions, the base stations 102 mayperform one or more of the following functions: transfer of user data,radio channel ciphering and deciphering, integrity protection, headercompression, mobility control functions (e.g., handover, dualconnectivity), inter-cell interference coordination, connection setupand release, load balancing, distribution for non-access stratum (NAS)messages, NAS node selection, synchronization, radio access network(RAN) sharing, multimedia broadcast multicast service (MBMS), subscriberand equipment trace, RAN information management (RIM), paging,positioning, and delivery of warning messages. The base stations 102 maycommunicate directly or indirectly (e.g., through the EPC 160) with eachother over backhaul links 134 (e.g., X2 interface). The backhaul links134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. There may be overlappinggeographic coverage areas 110. For example, the small cell 102′ may havea coverage area 110′ that overlaps the coverage area 110 of one or moremacro base stations 102. A network that includes both small cell andmacro cells may be known as a heterogeneous network. A heterogeneousnetwork may also include Home Evolved Node Bs (eNBs) (HeNBs), which mayprovide service to a restricted group known as a closed subscriber group(CSG). The communication links 120 between the base stations 102 and theUEs 104 may include uplink (UL) (also referred to as reverse link)transmissions from a UE 104 to a base station 102 and/or downlink (DL)(also referred to as forward link) transmissions from a base station 102to a UE 104. The communication links 120 may use MIMO antennatechnology, including spatial multiplexing, beamforming, and/or transmitdiversity. The communication links may be through one or more carriers.The base stations 102/UEs 104 may use spectrum up to Y MHz (e.g., 5, 10,15, 20 MHz) bandwidth per carrier allocated in a carrier aggregation ofup to a total of Yx MHz (x component carriers) used for transmission ineach direction. The carriers may or may not be adjacent to each other.Allocation of carriers may be asymmetric with respect to DL and UL(e.g., more or less carriers may be allocated for DL than for UL). Thecomponent carriers may include a primary component carrier and one ormore secondary component carriers. A primary component carrier may bereferred to as a primary cell (PCell) and a secondary component carriermay be referred to as a secondary cell (SCell).

The wireless communications system may further include a Wi-Fi accesspoint (AP) 150 in communication with Wi-Fi stations (STAs) 152 viacommunication links 154 in a 5 GHz unlicensed frequency spectrum. Whencommunicating in an unlicensed frequency spectrum, the STAs 152/AP 150may perform a clear channel assessment (CCA) prior to communicating inorder to determine whether the channel is available.

The small cell 102′ may operate in a licensed and/or an unlicensedfrequency spectrum. When operating in an unlicensed frequency spectrum,the small cell 102′ may employ LTE and use the same 5 GHz unlicensedfrequency spectrum as used by the Wi-Fi AP 150. The small cell 102′,employing LTE in an unlicensed frequency spectrum, may boost coverage toand/or increase capacity of the access network. LTE in an unlicensedspectrum may be referred to as LTE-unlicensed (LTE-U), licensed assistedaccess (LAA), or MuLTEfire.

The millimeter wave (mmW) base station 180 may operate in mmWfrequencies and/or near mmW frequencies in communication with the UE182. Extremely high frequency (EHF) is part of the RF in theelectromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and awavelength between 1 millimeter and 10 millimeters. Radio waves in theband may be referred to as a millimeter wave. Near mmW may extend downto a frequency of 3 GHz with a wavelength of 100 millimeters. The superhigh frequency (SHF) band extends between 3 GHz and 30 GHz, alsoreferred to as centimeter wave. Communications using the mmW/near mmWradio frequency band has extremely high path loss and a short range. ThemmW base station 180 may utilize beamforming 184 with the UE 182 tocompensate for the extremely high path loss and short range.

The EPC 160 may include a Mobility Management Entity (MME) 162, otherMMEs 164, a Serving Gateway 166, a Multimedia Broadcast MulticastService (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be incommunication with a Home Subscriber Server (HSS) 174. The MME 162 isthe control node that processes the signaling between the UEs 104 andthe EPC 160. Generally, the MME 162 provides bearer and connectionmanagement. All user Internet protocol (IP) packets are transferredthrough the Serving Gateway 166, which itself is connected to the PDNGateway 172. The PDN Gateway 172 provides UE IP address allocation aswell as other functions. The PDN Gateway 172 and the BM-SC 170 areconnected to the IP Services 176. The IP Services 176 may include theInternet, an intranet, an IP Multimedia Subsystem (IMS), a PS StreamingService (PSS), and/or other IP services. The BM-SC 170 may providefunctions for MBMS user service provisioning and delivery. The BM-SC 170may serve as an entry point for content provider MBMS transmission, maybe used to authorize and initiate MBMS Bearer Services within a publicland mobile network (PLMN), and may be used to schedule MBMStransmissions. The MBMS Gateway 168 may be used to distribute MBMStraffic to the base stations 102 belonging to a Multicast BroadcastSingle Frequency Network (MBSFN) area broadcasting a particular service,and may be responsible for session management (start/stop) and forcollecting eMBMS related charging information.

The base station may also be referred to as a Node B, evolved Node B(eNB), an access point, a base transceiver station, a radio basestation, a radio transceiver, a transceiver function, a basic serviceset (BSS), an extended service set (ESS), or some other suitableterminology. The base station 102 provides an access point to the EPC160 for a UE 104. Examples of UEs 104 include a cellular phone, a smartphone, a session initiation protocol (SIP) phone, a laptop, a personaldigital assistant (PDA), a satellite radio, a global positioning system,a multimedia device, a video device, a digital audio player (e.g., MP3player), a camera, a game console, a tablet, a smart device, a wearabledevice, or any other similar functioning device. The UE 104 may also bereferred to as a station, a mobile station, a subscriber station, amobile unit, a subscriber unit, a wireless unit, a remote unit, a mobiledevice, a wireless device, a wireless communications device, a remotedevice, a mobile subscriber station, an access terminal, a mobileterminal, a wireless terminal, a remote terminal, a handset, a useragent, a mobile client, a client, or some other suitable terminology.

Referring again to FIG. 1, in certain aspects, UE 104, base station 102,and/or the mmW base station 180 may be configured to communicate withdifferent numerology configurations and/or with transmission gaps withina subframe (198).

FIG. 2A is a diagram 200 illustrating an example of a DL frame structurein LTE. FIG. 2B is a diagram 230 illustrating an example of channelswithin the DL frame structure in LTE. FIG. 2C is a diagram 250illustrating an example of an UL frame structure in LTE. FIG. 2D is adiagram 280 illustrating an example of channels within the UL framestructure in LTE. Other wireless communication technologies may have adifferent frame structure and/or different channels. In LTE, a frame (10ms) may be divided into 10 equally sized subframes. Each subframe mayinclude two consecutive time slots. A resource grid may be used torepresent the two time slots, each time slot including one or more timeconcurrent resource blocks (RBs) (also referred to as physical RBs(PRBs)). The resource grid is divided into multiple resource elements(REs). In LTE, for a normal cyclic prefix, an RB contains 12 consecutivesubcarriers in the frequency domain and 7 consecutive symbols (for DL,OFDM symbols; for UL, SC-FDMA symbols) in the time domain, for a totalof 84 REs. For an extended cyclic prefix, an RB contains 12 consecutivesubcarriers in the frequency domain and 6 consecutive symbols in thetime domain, for a total of 72 REs. The number of bits carried by eachRE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry DL reference (pilot)signals (DL-RS) for channel estimation at the UE. The DL-RS may includecell-specific reference signals (CRS) (also sometimes called common RS),UE-specific reference signals (UE-RS), and channel state informationreference signals (CSI-RS). FIG. 2A illustrates CRS for antenna ports 0,1, 2, and 3 (indicated as R₀, R₁, R₂, and R₃, respectively), UE-RS forantenna port 5 (indicated as R₅), and CSI-RS for antenna port 15(indicated as R). FIG. 2B illustrates an example of various channelswithin a DL subframe of a frame. The physical control format indicatorchannel (PCFICH) is within symbol 0 of slot 0, and carries a controlformat indicator (CFI) that indicates whether the physical downlinkcontrol channel (PDCCH) occupies 1, 2, or 3 symbols (FIG. 2B illustratesa PDCCH that occupies 3 symbols). The PDCCH carries downlink controlinformation (DCI) within one or more control channel elements (CCEs),each CCE including nine RE groups (REGs), each REG including fourconsecutive REs in an OFDM symbol. A UE may be configured with aUE-specific enhanced PDCCH (ePDCCH) that also carries DCI. The ePDCCHmay have 2, 4, or 8 RB pairs (FIG. 2B shows two RB pairs, each subsetincluding one RB pair). The physical hybrid automatic repeat request(ARQ) (HARQ) indicator channel (PHICH) is also within symbol 0 of slot 0and carries the HARQ indicator (HI) that indicates HARQ acknowledgement(ACK)/negative ACK (NACK) feedback based on the physical uplink sharedchannel (PUSCH). The primary synchronization channel (PSCH) is withinsymbol 6 of slot 0 within subframes 0 and 5 of a frame, and carries aprimary synchronization signal (PSS) that is used by a UE to determinesubframe timing and a physical layer identity. The secondarysynchronization channel (SSCH) is within symbol 5 of slot 0 withinsubframes 0 and 5 of a frame, and carries a secondary synchronizationsignal (SSS) that is used by a UE to determine a physical layer cellidentity group number. Based on the physical layer identity and thephysical layer cell identity group number, the UE can determine aphysical cell identifier (PCI). Based on the PCI, the UE can determinethe locations of the aforementioned DL-RS. The physical broadcastchannel (PBCH) is within symbols 0, 1, 2, 3 of slot 1 of subframe 0 of aframe, and carries a master information block (MIB). The MIB provides anumber of RBs in the DL system bandwidth, a PHICH configuration, and asystem frame number (SFN). The physical downlink shared channel (PDSCH)carries user data, broadcast system information not transmitted throughthe PBCH such as system information blocks (SIBs), and paging messages.

As illustrated in FIG. 2C, some of the REs carry demodulation referencesignals (DM-RS) for channel estimation at the eNB. The UE mayadditionally transmit sounding reference signals (SRS) in the lastsymbol of a subframe. The SRS may have a comb structure, and a UE maytransmit SRS on one of the combs. The SRS may be used by an eNB forchannel quality estimation to enable frequency-dependent scheduling onthe UL. FIG. 2D illustrates an example of various channels within an ULsubframe of a frame. A physical random access channel (PRACH) may bewithin one or more subframes within a frame based on the PRACHconfiguration. The PRACH may include six consecutive RB pairs within asubframe. The PRACH allows the UE to perform initial system access andachieve UL synchronization. A physical uplink control channel (PUCCH)may be located on edges of the UL system bandwidth. The PUCCH carriesuplink control information (UCI), such as scheduling requests, a channelquality indicator (CQI), a precoding matrix indicator (PMI), a rankindicator (RI), and HARQ ACK/NACK feedback. The PUSCH carries data, andmay additionally be used to carry a buffer status report (BSR), a powerheadroom report (PHR), and/or UCI.

FIG. 3 is a block diagram of an eNB 310 in communication with a UE 350in an access network. In the DL, IP packets from the EPC 160 may beprovided to a controller/processor 375. The controller/processor 375implements layer 3 and layer 2 functionality. Layer 3 includes a radioresource control (RRC) layer, and layer 2 includes a packet dataconvergence protocol (PDCP) layer, a radio link control (RLC) layer, anda medium access control (MAC) layer. The controller/processor 375provides RRC layer functionality associated with broadcasting of systeminformation (e.g., MIB, SIBs), RRC connection control (e.g., RRCconnection paging, RRC connection establishment, RRC connectionmodification, and RRC connection release), inter radio access technology(RAT) mobility, and measurement configuration for UE measurementreporting; PDCP layer functionality associated with headercompression/decompression, security (ciphering, deciphering, integrityprotection, integrity verification), and handover support functions; RLClayer functionality associated with the transfer of upper layer packetdata units (PDUs), error correction through ARQ, concatenation,segmentation, and reassembly of RLC service data units (SDUs),re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; andMAC layer functionality associated with mapping between logical channelsand transport channels, multiplexing of MAC SDUs onto transport blocks(TBs), demultiplexing of MAC SDUs from TBs, scheduling informationreporting, error correction through HARQ, priority handling, and logicalchannel prioritization. The transmit (TX) processor 316 and the receive(RX) processor 370 implement layer 1 functionality associated withvarious signal processing functions. Layer 1, which includes a physical(PHY) layer, may include error detection on the transport channels,forward error correction (FEC) coding/decoding of the transportchannels, interleaving, rate matching, mapping onto physical channels,modulation/demodulation of physical channels, and MIMO antennaprocessing. The TX processor 316 handles mapping to signalconstellations based on various modulation schemes (e.g., binaryphase-shift keying (BPSK), quadrature phase-shift keying (QPSK),M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an OFDM subcarrier,multiplexed with a reference signal (e.g., pilot) in the time and/orfrequency domain, and then combined together using an Inverse FastFourier Transform (IFFT) to produce a physical channel carrying a timedomain OFDM symbol stream. The OFDM stream is spatially precoded toproduce multiple spatial streams. Channel estimates from a channelestimator 374 may be used to determine the coding and modulation scheme,as well as for spatial processing. The channel estimate may be derivedfrom a reference signal and/or channel condition feedback transmitted bythe UE 350. Each spatial stream may then be provided to a differentantenna 320 via a separate transmitter 318TX. Each transmitter 318TX maymodulate an RF carrier with a respective spatial stream fortransmission.

At the UE 350, each receiver 354RX receives a signal through itsrespective antenna 352. Each receiver 354RX recovers informationmodulated onto an RF carrier and provides the information to the receive(RX) processor 356. The TX processor 368 and the RX processor 356implement layer 1 functionality associated with various signalprocessing functions. The RX processor 356 may perform spatialprocessing on the information to recover any spatial streams destinedfor the UE 350. If multiple spatial streams are destined for the UE 350,they may be combined by the RX processor 356 into a single OFDM symbolstream. The RX processor 356 then converts the OFDM symbol stream fromthe time-domain to the frequency domain using a Fast Fourier Transform(FFT). The frequency domain signal comprises a separate OFDM symbolstream for each subcarrier of the OFDM signal. The symbols on eachsubcarrier, and the reference signal, are recovered and demodulated bydetermining the most likely signal constellation points transmitted bythe eNB 310. These soft decisions may be based on channel estimatescomputed by the channel estimator 358. The soft decisions are thendecoded and deinterleaved to recover the data and control signals thatwere originally transmitted by the eNB 310 on the physical channel. Thedata and control signals are then provided to the controller/processor359, which implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with a memory 360 thatstores program codes and data. The memory 360 may be referred to as acomputer-readable medium. In the UL, the controller/processor 359provides demultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, and control signalprocessing to recover IP packets from the EPC 160. Thecontroller/processor 359 is also responsible for error detection usingan ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality described in connection with the DLtransmission by the eNB 310, the controller/processor 359 provides RRClayer functionality associated with system information (e.g., MIB, SIBs)acquisition, RRC connections, and measurement reporting; PDCP layerfunctionality associated with header compression/decompression, andsecurity (ciphering, deciphering, integrity protection, integrityverification); RLC layer functionality associated with the transfer ofupper layer PDUs, error correction through ARQ, concatenation,segmentation, and reassembly of RLC SDUs, re-segmentation of RLC dataPDUs, and reordering of RLC data PDUs; and MAC layer functionalityassociated with mapping between logical channels and transport channels,multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs,scheduling information reporting, error correction through HARQ,priority handling, and logical channel prioritization.

Channel estimates derived by a channel estimator 358 from a referencesignal or feedback transmitted by the eNB 310 may be used by the TXprocessor 368 to select the appropriate coding and modulation schemes,and to facilitate spatial processing. The spatial streams generated bythe TX processor 368 may be provided to different antenna 352 viaseparate transmitters 354TX. Each transmitter 354TX may modulate an RFcarrier with a respective spatial stream for transmission.

The UL transmission is processed at the eNB 310 in a manner similar tothat described in connection with the receiver function at the UE 350.Each receiver 318RX receives a signal through its respective antenna320. Each receiver 318RX recovers information modulated onto an RFcarrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 thatstores program codes and data. The memory 376 may be referred to as acomputer-readable medium. In the UL, the controller/processor 375provides demultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, control signal processingto recover IP packets from the UE 350. IP packets from thecontroller/processor 375 may be provided to the EPC 160. Thecontroller/processor 375 is also responsible for error detection usingan ACK and/or NACK protocol to support HARQ operations.

In wireless communication systems that support 5G or NR protocols,subframes used for communication may have different numerology options.Numerology options may refer to the characteristics of the subframe suchas a tone spacing within each symbol of the subframe, a symbol durationfor each symbol of the subframe, a number of symbols in the subframe,etc. As discussed above, a subframe may include a control channel (e.g.,the PDCCH) and a data channel (e.g., the PDSCH). In an aspect, thecontrol channel and the data channel within the subframe may havedifferent numerologies. As such, a need exists to signal the numerologyof the subframe to users and to determine whether and how to multiplexthe control channel and the data channel into the subframe.

FIG. 4 is a diagram 400 of a method for indicating a numerologyconfiguration. Referring to FIG. 4, a UE 404 may obtain initial accessto a network via a base station 402 (e.g., the base station 102 or themmW base station 180). For initial system access, a default numerologyconfiguration may be used by the base station 402. The defaultnumerology configuration may be pre-configured at the network and/orknown by the base station 402 and the UE 404. The default numerologyconfiguration may indicate a default tone spacing for each of thesymbols in a subframe. Based on the default numerology configuration,the base station 402 may utilize a default tone spacing for a symbolwithin a subframe (e.g., symbol 0) for transmitting the PBCH. The PBCHmay include the MIB, which provides system information for purposes ofinitiating a random access channel (RACH) procedure for initial systemaccess. Because the default numerology configuration is used, the UE 404may be able to receive and decode the PBCH to obtain the information forthe RACH procedure. Subsequently, the UE 404 may initiate the RACHprocedure by transmitting a first RACH message to the base station 402,and the base station 402 may respond by transmitting a second RACHmessage to the UE 404. In an aspect, the second RACH message may includea PDCCH and a PDSCH that contains an uplink resource allocation fortransmitting additional messages to the base station 402 for purposes ofgaining network access. Like the PBCH, the PDCCH may also be transmittedusing the default numerology configuration, or another numerologyconfiguration that is indicated by the information sent by PBCH, whichenables the UE 404 to properly receive and decode the PDCCH.

Once the UE 404 obtains access to the network, the base station 402 maychange the numerology configuration in subsequent subframes. In oneexample, referring to FIG. 4, the base station 402 may decide to changethe numerology in subframe 8 of the same frame or in a subsequent (orlater) frame. In this example, referring to FIG. 4, subframe 8 has 15symbols, although a different number of symbols may also be used. The 15symbols have symbol indices 0 to 14. Symbol 0 may include a controlchannel (e.g., the PDCCH) and may have 120 kHz tone spacing. Symbol 1may also have 120 kHz tone spacing. Symbols 2-14 may include a datachannel (e.g., the PDSCH) and may have a 60 kHz tone spacing for data.Symbols with a greater tone spacing have a shorter symbol duration.Accordingly, symbols 0 and 1 in subframe 8, which have double the tonespacing as compared to symbols 2-14 may have half the symbol duration ofsymbols 2-14. Other numerology configurations (e.g., tone spacings) mayalso be used.

In other configurations, the numerology configuration may beUE-specific, common to all UEs associated with the base station 402, orcommon to a subset of UEs associated with the base station 402. In oneexample, the base station 402 may have a list of available numerologyconfigurations and may select from the list of numerology configurationsbased on a UE identifier. In another example, the base station 402 maymeasure channel conditions (e.g., determine which frequencies arebusier) and select a numerology configuration based on the measuredchannel conditions. In yet another example, the base station 402 mayreceive channel feedback from one or more UEs, and may select thenumerology configuration based on channel feedback that may be specificto one UE or common to a subset of UEs.

After determining the numerology configuration, the base station 402 mayneed a method of signaling the numerology configuration to the UE 404.Without such signaling, if the base station 402 switches numerologyconfigurations, the UE 404 may have to blindly decode the information(e.g., the control channel) because the base station 402 and the UE 404may have different assumptions about the numerology configurations beingused in various subframes. To signal the numerology configuration, thebase station 402 may transmit an indication of the numerologyconfiguration in a subframe, such as a fallback subframe. The basestation 402 may determine one or more fallback subframes 406 (e.g.,subframes 5 and 6) and determine a numerology configuration to use forthe one or more fallback subframes 406. In an aspect, the one or morefallback subframes 406 may be UE-specific (each UE is allocated aspecific set of fallback subframes), common to all UEs, or specific to asubset of UEs. For example, the base station 402 may determine when tosend the one or more fallback subframes 406 based on a UE identifier, aUE group identifier, or based on pre-configured system information. Theone or more fallback subframes 406 may have a numerology configurationthat is known the UE 404 (or another UE for which the fallback subframeis intended). For example, the base station 402 may determine thenumerology configuration to use for communicating in the one or morefallback subframes 406 based on a UE identifier, a UE group identifier,or pre-configured system information (e.g., all fallback subframes arerequired to use a certain numerology configuration). The one or morefallback subframes 406 (e.g., subframes 5 and 6) may indicate anumerology configuration to be used for communication between the basestation 402 and the UE 404 in future or subsequent communications (e.g.,within subframe 8). For example, a fallback subframe may identify aparticular subframe within a frame on which the numerology configurationis to change and the numerology configuration to be used in theparticular subframe. Because the UE 404 knows the numerologyconfiguration of the fallback subframe, the UE 404 may be able toaccurately decode the information in the one or more fallback subframes406 to determine the numerology configuration for future communications.In an aspect, the one or more fallback subframes 406 may indicate anumerology configuration to be used for any type of future subframe,including future fallback subframes.

As an example, referring to FIG. 4, the numerology configuration forsubframe 8 is associated with a first tone spacing for symbols 0 and 1and associated with a control channel and a gap symbol, which maycontain control information or reference signals. The numerologyconfiguration may also be associated with a second tone spacing forsymbols 2 to 14 on which a data channel is to be transmitted. Thenumerology configuration may indicate the first tone spacing for symbols0 and 1 and/or the second tone spacing for symbols 2 to 14.

In another configuration, the base station 402 may determine thenumerology configuration to be used for communicating with the UE 404based on a handshaking procedure. The base station 402 and the UE 404may engage in a handshaking procedure before the base station 402switches to a different numerology configuration. In this configuration,the base station 402 may transmit an activation command to the UE 404that indicates when the numerology configuration will change or takeeffect. For example, the activation command may indicate the numerologyconfiguration (e.g., tone spacings on different symbols for control anddata) and one or more subframes in which the numerology configurationwill take effect. In an aspect, the activation command may be includedwithin the one or more fallback subframes 406. Upon receiving theactivation command, the UE 404 may transmit an acknowledgment 408 of theactivation command to the base station 402 if the UE 404 is capable ofswitching numerology configurations at the indicated time. After thebase station 402 receives the acknowledgment 408, the base station 402may begin transmitting a set of subframes 410 to the UE 404 based on thedetermined numerology configuration. In an aspect, instead of providingthe acknowledgment 408, the UE 404 may negotiate the numerologyconfiguration by providing a different numerology configuration to thebase station 402. If the base station 402 agrees, then the base station402 may retransmit the numerology configuration to the UE 404, and theUE 404 may acknowledge the retransmission. Upon receiving theacknowledgment, the base station 402 may be permitted to switch to thedifferent numerology configuration.

In another configuration, the base station 402 may want to indicate tothe UE 404 when to expect the one or more fallback subframes 406. Forexample, the base station 402 may signal a periodicity with which theone or more fallback subframes 406 will be transmitted (e.g., everyother frame, subframe 0 in every frame, etc.). In one aspect, the basestation 402 may signal when to expect the one or more fallback subframes406 in a MIB, SIB, and/or in RRC signaling.

In another configuration, the base station 402 may not need to signalwhen the UE 404 is to expect the one or more fallback subframes 406because that information may be pre-configured. For example, all the UEsmay know to expect the base station 402 to transmit fallback subframesat certain points in time or in certain subframes within a frame. Inanother configuration, the determined numerology configuration may besignaled in a MIB, a SIB, or in RRC signaling. In another aspect, thenumerology configuration may be pre-configured. For example, certainsubframe indices may be associated with a first numerology configurationand other subframe indices may be associated with a second numerologyconfiguration. The first numerology configuration may be the same ordifferent from the second numerology configuration. In this example, thefirst and second numerology configurations and the subframe indices towhich the configurations correspond may be known to the UEs and the basestation 402. In another aspect, the numerology configuration may befixed or semi-persistent, or may change dynamically.

FIG. 5 is a diagram 500 of a method for supporting different numerologyconfigurations for data and control channels. Referring to FIG. 5, asubframe 506, such as subframe 8, within a frame may have a numerologyconfiguration such that different symbols in the subframe have differentnumerologies. In this example, subframe 8 has 15 symbols, although adifferent number of symbols may also be used. The 15 symbols have symbolindices 0 to 14. Symbol 0 may include a control channel (e.g., thePDCCH) and may have 120 kHz tone spacing. Symbol 1 (a gap symbol) mayalso have 120 kHz tone spacing. Symbols 2-14 may include a data channel(e.g., the PDSCH) and may have a 60 kHz tone spacing for data. Symbolswith a greater tone spacing have a shorter symbol duration. Accordingly,symbols 0 and 1 in subframe 8, which have double the tone spacing ascompared to symbols 2-14 may have half the symbol duration of symbols2-14. Other numerology configurations (e.g., tone spacings) may also beused.

Referring to FIG. 5, a base station 502 may determine a nominalnumerology on which to base a numerology configuration. In an aspect,the nominal numerology may be preconfigured. For example, the nominalnumerology may be associated with a 60 kHz tone spacing within a symbol.In one configuration, the base station 502 may determine to use anumerology configuration in which the control channel and the datachannel have the same numerology such as a 60 kHz tone spacing (1× thenominal numerology) or a 120 kHz tone spacing (2× the nominalnumerology).

In another configuration, the base station 502 may determine to use anumerology configuration in which the control channel in symbol 0 (e.g.,a first set of symbols) and the data channel in symbols 2 to 14 (e.g., asecond set of symbols) may have different numerologies. In one aspect,the tone spacing for the control channel in symbol 0 may have twice thetone spacings as the data channel in symbols 2-14 as shown in subframe8. Assuming the nominal tone spacing is 60 kHz, then the control channelmay have a tone spacing that is 2× the nominal tone spacing, and thedata channel may have a tone spacing that is 1× the nominal tonespacing. Other multiples of the nominal tone spacing may also be used.

In another configuration, the base station 502 may also determine toutilize symbol 1 for transmitting the data channel. When the controlchannel and the data channel have the same numerology, the base station502 may determine to time-division multiplex the control channel and thedata channel onto adjacent symbols, such as symbol 0 for the controlchannel and symbol 1 for the data channel (along with the remainingsymbols within the subframe for the data channel). However, when thecontrol channel and the data channel have different numerologies, asshown in subframe 8, then the base station 502 may determine not totime-division multiplex the control channel in symbol 0 with the datachannel in symbol 1.

In another configuration, the base station 502 may determine to utilizesymbol 1 (the gap symbol) for transmitting control information. Forexample, the base station 502 may utilize symbol 1 to transmit referencesignals or L1 control signals. In this configuration, symbol 1 may havea same or different numerology (e.g., tone spacing) as symbol 0.

Referring to FIG. 5, the base station 502 may transmit a signal insubframe 8 to a UE 504. The UE 504 may receive the signal in thesubframe in which a first tone spacing (e.g., 120 kHz) is used for acontrol channel in symbol 0 and a second tone spacing (e.g., 60 kHz) isused for a data channel in symbols 2 to 14. The subframe may alsoinclude a gap symbol that also uses the first tone spacing. The UE 504may decode the subframe based on the numerology configuration of thesubframe. For example, the UE 504 may determine the first and secondtone spacings and extract the control information and data based on thefirst and second tone spacings. The UE 504 may determine the first andsecond tone spacings based on a received fallback subframe as describedin FIG. 4. The fallback subframe may also indicate the tone spacing inthe gap symbol, and the UE 504 may extract either control information ordata from the gap symbol.

Although FIG. 5 illustrates using the gap symbol when multiplexing thedownlink control channel and the downlink data channel, a gap symbol mayalso be used in the uplink context. For example, when the UE 504multiplexes the uplink control channel, which may have a first set ofsymbols, and the uplink data channel, which may have a second set ofsymbols, within a subframe, the UE 504 may separate the two channelsusing one or more gap symbols.

Thus far, FIG. 5 has illustrated that the gap symbol (e.g., symbol 1)may be used when control and data are multiplexed with differentnumerologies within a subframe (or a slot). The gap symbol serves topreserve the alignment of a set of symbols (e.g., symbols 2-14) with thenominal symbol boundaries as depicted in FIG. 5. Without the gap symbol,symbols 2-14 may not align with the nominal symbol boundaries. AlthoughFIG. 5 illustrates a single gap symbol, a different number of gapsymbols may also be used. The use of gap symbols within a subframe mayalso be extended to other scenarios.

FIGS. 6A-D illustrate additional uses of gap symbols (or transmissiongaps) within a subframe. Aside from using gap symbols when multiplexinga control channel (uplink or downlink) with a data channel (uplink ordownlink) having different numerologies, the gap symbols may also beused if the control channel has a different transmission bandwidthcompared to the data channel. FIG. 6A illustrates a subframe 600 with acontrol channel, a data channel, and a gap symbol. The control channelmay have a narrower transmission bandwidth (e.g., 10 MHz bandwidth) thana data channel (e.g., 20 MHz bandwidth) or vice versa. The difference inbandwidth may occur when a UE, for example, operates in a power savingmode. In this mode, the UE may need time, after receiving from a basestation one or more control symbol(s) with a narrower bandwidth, toadjust its receiver (or receive chain) to collect samples of the dataover a wider bandwidth. The gap symbol 1 in between the control channel(symbol 0) and the data channels (symbols 2-14) provides the UE withadditional time to adjust its receiver. Although FIG. 6A describes theusage of the gap symbol in the downlink context, the same methods,principles, and techniques may be applied in the uplink context. Forexample, the base station may receive the control channel with anarrower bandwidth and receive the data channel with a wider bandwidth.The first set of symbols corresponding to the control channel may beseparated from the second set of symbols corresponding to the datachannel by one or more gap symbols. Although FIG. 6A illustrates thecontrol channel and the data channel having different numerologies, thegap symbol may be utilized when the data and control channels have thesame numerology but different bandwidths.

FIG. 6B illustrates a subframe 620 with an uplink channel, a downlinkchannel, and a gap symbol. Although one gap symbol is illustrated,additional gap symbols may be used to separate the uplink channel andthe downlink channel. In this example, when a UE switches fromtransmission mode (e.g., transmitting on the uplink channel) toreception mode (e.g., receiving on the downlink channel) and vice versa,the gap symbol may be utilized to provide the UE time to switch betweenmodes during a subframe. In one configuration, as shown in FIG. 6B, theUE may transmit uplink control information, and then after a gap symbol,switch to receiving downlink data. In another configuration, the UE mayreceive downlink control information and switch to transmit uplink datawithin a subframe. In another configuration, the UE may switch fromreceiving downlink data to transmitting uplink control information. Anytime there is a switch in allocated resources (e.g., uplink to downlinkor vice versa), one or more gap symbols may be used to separate thetypes of resources. The gap symbols may be even more beneficial when theswitch involves channels associated with symbols of differentnumerologies or bandwidths. The aforementioned principles may also applyto base stations in addition to UEs.

FIG. 6C illustrates a subframe 640 with a first data channel, a gapsymbol, and a second data channel. Although one gap symbol isillustrated, additional gap symbols may be used to separate the firstdata channel and the second data channel. In one configuration, thefirst data channel may be used to provide a first service and the seconddata channel may be used to provide a second service. The second servicemay be different from the first service because the second service mayhave different quality of service requirements, for example. In anotherconfiguration, the first and second data channels may have differentnumerologies. In another configuration, the first and second datachannels may have different bandwidths. In another configuration, thefirst channel may be an ultra-reliable and low-latency (URLLC) channeland the second channel may be an enhanced mobile broadband (eMBB)channel. Because different services may have different numerologies dueto the different use cases and requirements, a gap symbol may be used toseparate a first set of symbols (e.g., one or more symbols) associatedwith the first channel from the second set of symbols (e.g., one or moresymbols) associated with the second channel. In an aspect, although thefirst data channel has one symbol, the first data channel may have adifferent number of symbols. In another aspect, although the subframe640 does not illustrate control symbols, the subframe 640 may have oneor more control symbols.

FIG. 6D illustrates a subframe 660 with a first control channel, asecond control channel, multiple gap symbols, and a data channel. Insome instances, multiple control symbols of the same or differentnumerologies may be implemented in a subframe. For example, a basestation may transmit a single or multiple control symbols for beammanagement (or beam training) in a first control channel within a slot.The base station may transmit reference signals in the control symbolswithin the first control channel. In an aspect, the control symbols forbeam management may be known as CSI-RS symbols, which may be transmittedin symbols 0 and 1 of the subframe 660. The CSI-RS symbols may have adifferent or the same numerology than other control symbols in a secondcontrol channel (at symbol 3). In an aspect, a gap symbol 2 may separatethe first and second control channels. Another gap symbol 4 may separatethe second control channel from the data channel located at data symbols5-14. As such, because the CSI-RS symbols may have differentnumerologies than other control and/or data symbols, one or more gapsymbols may be used when multiplexing symbols used for beam managementwith other symbols. FIG. 7 is a flowchart 700 of a method of wirelesscommunication. The method may be performed by a base station (e.g., thebase station 102, the base stations 402, 502, the mmW base station 180).At 702, the base station may determine a numerology configuration to beused for communication with a UE in one or more fallback subframes. Inan aspect, the determined numerology configuration may be fixed,semi-persistent, or change dynamically. For example, referring to FIG.4, the base station may be the base station 402. The base station 402may determine a numerology configuration to be used for communicatingwith the UE 404. In an aspect, the base station 402 may determine thenumerology configuration based on a UE identifier, a UE groupidentifier, or pre-configured system information (e.g., known to the UE404). That is, the numerology configuration may be UE-specific, commonto all UEs, or common to a subset of UEs associated with the basestation 402. The numerology configuration may be a default numerologyconfiguration that is known to the UE.

At 704, the base station may determine one or more fallback subframes.In an aspect, the base station may determine the one or more fallbacksubframes by determining when to transmit the one or more fallbacksubframes. For example, referring to FIG. 4, the base station 402 maydetermine one or more fallback subframes 406 by determining when totransmit the one or more fallback subframes 406. In an aspect, thetiming of when to transmit the one or more fallback subframes 406 may beUE-specific, common to all UEs associated with the base station 402, orcommon to a subset of UEs associated with the base station 402. In thisaspect, the base station 402 may determine when to transmit based on aUE identifier or a UE group identifier. In another aspect, the timing ofwhen to transmit the one or more fallback subframes 406 may bepre-configured (e.g., during subframe 1 and/or 2 of every frame). In anaspect, the base station 402 may indicate when the one or more fallbacksubframes 406 will be transmitted in a MIB, SIB, or RRC signaling.

At 706, the base station may communicate with the UE within the one ormore fallback subframes based on the determined numerologyconfiguration. The determined numerology configuration may be known tothe UE. For example, referring to FIG. 4, the base station 402 maycommunicate with the UE 404 within the one or more fallback subframes406. In one configuration, the base station 402 may communicate with theUE 404 by transmitting the one or more fallback subframes 406 to the UE404.

At 708, the base station may transmit one or more signals to indicate,to the UE, a second numerology configuration to be used for futurecommunications with the UE. The second numerology configuration mayindicate a numerology configuration for subsequent subframes and/orsubsequent fallback frames. For example, referring to FIG. 4, the basestation 402 may transmit one or more signals to indicate, to the UE 404,a second numerology configuration to be used for future communicationswith the UE 404. In an aspect, the, the one or more signals may betransmitted within a subset of the one or more fallback subframes 406.

In another configuration, the base station may engage in a handshakingprocedure before switching numerology configurations. In thisconfiguration, at 710, the base station may transmit an activationcommand indicating when the second numerology configuration is to takeeffect. The activation command may be transmitted in a fallbacksubframe. For example, referring to FIG. 4, the base station 402 maytransmit the activation command that indicates when the secondnumerology configuration is to take effect. The activation command maybe transmitted in the one or more fallback subframes 406 or elsewhere.

In this configuration, at 712, the base station may receive anacknowledgment from the UE based on the transmitted activation command.For example, referring to FIG. 4, the base station 402 may receive theacknowledgment 408 from the UE 404 based on the transmitted activationcommand, and the acknowledgment 408 may indicate that the UE 404acknowledges the change to the second numerology configuration insubsequent subframes received from the base station 402.

At 714, the base station may transmit to the UE a set of subframes withthe second numerology configuration after receiving the acknowledgmentfrom the UE. For example, referring to FIG. 4, the base station 402 maytransmit to the UE 404 the set of subframes 410 after receiving theacknowledgment 408 from the UE 404. In another configuration, the basestation 402 may not engage in a handshake, and therefore, may transmitthe set of subframes 410 without receiving the acknowledgment 408.

FIG. 8 is a flowchart 800 of a method of wireless communication. Themethod may be performed by a first wireless device (e.g., the basestation 102, the base stations 402, 502, the mmW base station 180, theUE 104, the UE 182, the UE 404, or the UE 504).

At 802, the first wireless device may determine a numerologyconfiguration to be used for a subframe. The numerology configurationmay be based on a nominal numerology (e.g., 60 kHz tone spacing). Thenumerology configuration may include a first tone spacing in thesubframe for a first set of symbols (e.g., a control channel with one ormore symbols) and a second tone spacing in the subframe for a second setof symbols (e.g., a data channel with one or more symbols). In anaspect, the first tone spacing is the same as the second tone spacing.In another aspect, the first tone spacing is different from the secondtone spacing. In another aspect, the first tone spacing is an integermultiple of a tone spacing of the nominal numerology and the second tonespacing is a second integer multiple of the nominal numerology. In oneexample, referring to FIG. 5, the first wireless device may be the basestation 502. The base station 502 may determine a nominal numerology fora subframe. Based on the nominal numerology, the base station 502 maydetermine a numerology configuration to be used for a subframe. The basestation 502 may determine the numerology configuration by determining afirst tone spacing (e.g., 120 kHz tone spacing) for a control channel,and the first tone spacing is an integer multiple (e.g., multiple of 2)of the nominal numerology (e.g., 60 kHz tone spacing). The base station502 may further determine the numerology configuration by determining asecond tone spacing (e.g., 60 kHz) for a data channel, and the secondtone spacing is an integer multiple (e.g., multiple of 1) of the nominalnumerology.

At 804, the first wireless device may determine whether to TDM the firstset of symbols with the second set of symbols into adjacent locationsbased on the determined numerology configuration of the subframe. Forexample, referring to FIG. 5, the base station 502 may determine whetherto TDM the control channel with the data channel onto adjacent symbolsbased on the determined numerology configuration of the subframe. On theone hand, the base station 502 may determine not to TDM the controlchannel with the data channel if the adjacent symbols have differenttone spacings (e.g., 60 kHz and 120 kHz) and the transmission of the twoadjacent symbol will overlap with symbol boundaries corresponding to thenominal numerology. On the other hand, the base station 502 maydetermine to TDM the control channel with the data channel if theadjacent symbols have the same tone spacings. In another example, thebase station 502 may determine to TDM the control channel with the datachannel even if the adjacent symbols have different tone spacings if thetransmission of the adjacent symbols will not overlap with symbolboundaries corresponding to the nominal numerology.

At 806, the first wireless device may communicate with a second wirelessdevice within the subframe based on the determined numerologyconfiguration. In one example, referring to FIG. 5, the base station 502may communicate by transmitting the subframe 506 to the UE 504. Inanother example, referring to FIG. 5, if the first wireless device isthe UE 504, then the UE 504 may communicate with the base station 502(the second wireless device) by receiving the subframe 506 and bydecoding the subframe (as further discussed in FIG. 10 below). The UE504 may determine the numerology configuration based on the methods andtechniques discussed with respect to FIG. 4, for example.

FIG. 9 is a flowchart 900 of a method of wireless communication. Themethod may be performed by a UE (e.g., the UE 104 or the UE 182). At902, the UE may determine one or more fallback subframes. In an aspect,the UE may determine when a base station will transmit the one or morefallback subframes. For example, referring to FIG. 4, the UE may be theUE 404. The UE 404 may determine one or more fallback subframes bydetermining when the base station 402 will transmit one or more fallbacksubframes 406. In one aspect, the UE 404 may determine when the basestation 402 will transmit the one or more fallback subframes 406 basedon a UE identifier or a UE group identifier. That is, the UE 404 may bepreconfigured to know when the base station 402 will transmit one ormore fallback subframes 406 according to an identifier. In anotheraspect, the UE 404 may receive signaling from the base station 402, viathe MIB, SIB, or RRC signaling, that indicates when the base station 402will transmit the one or more fallback subframes 406. The MIB, SIB,and/or RRC signaling may further indicate the numerology configurationto be used in the one or more fallback subframes 406. In another aspect,the numerology configuration to be used for the one or more fallbacksubframes 406 may be preconfigured within the UE 404.

At 904, the UE may determine a numerology configuration to be used forcommunication with the base station within the one or more fallbacksubframes. In an aspect, the UE may know the determined numerologyconfiguration to be used in the one or more fallback subframes based ona received MIB or SIB. In another aspect, the numerology configurationmay be preconfigured within the UE. For example, referring to FIG. 4,the UE 404 may determine the numerology configuration to be used forcommunicating with the base station 402 within the one or more fallbacksubframes 406. The UE 404 may determine the numerology by receiving aMIB or a SIB and by determining the numerology configuration indicatedin the MIB or the SIB. In another configuration, the numerologyconfiguration may be preconfigured into the UE 404.

At 906, the UE may communicate with the base station within one or morefallback subframes based on the determined numerology configuration. TheUE may receive the one or more fallback subframes in downlinktransmissions. The UE may also use the one or more fallback frames totransmit information to the base station in uplink transmissions. Forexample, referring to FIG. 4, the UE 404 may communicate with the basestation 402 within the one or more fallback subframes 406. The UE 404may communicate within the one or more fallback subframes by receivingone or more fallback subframes from the base station 402.

At 910, the UE may receive one or more signals from the base stationindicating a second numerology configuration to be used for futurecommunications with the base station. In an aspect, the one or moresignals are transmitted in the fallback subframes. For example,referring to FIG. 4, the UE 404 may receive one or more signals from thebase station 402 indicating a second numerology configuration to be usedfor subsequent communications with the base station 402. The one or moresignals may be received in the one or more fallback subframes 406.

In another configuration, the UE and the base station may perform ahandshaking procedure before transitioning between different numerologyconfigurations. In this configuration, at 910, the UE may receive anactivation command indicating when a second numerology configuration isto take effect. The activation command may be transmitted in a fallbacksubframe. For example, referring to FIG. 4, the UE 404 may receive theactivation command that indicates when the second numerologyconfiguration is to take effect. The activation command may betransmitted in the one or more fallback subframes 406 or elsewhere.

At 912, the UE may transmit an acknowledgment to the base station basedon the received activation command. For example, referring to FIG. 4,the UE 404 may transmit the acknowledgment 408 to the base station 402based on the received activation command, and the acknowledgment 408 mayindicate that the UE 404 acknowledges the change to the secondnumerology configuration in subsequent subframes received from the basestation 402.

At 914, the UE may receive a set of subframes with the second numerologyconfiguration after transmitting the acknowledgment. For example,referring to FIG. 4, the UE 404 may receive the set of subframes 410after transmitting the acknowledgment 408 to the base station 402. Inanother configuration, the UE 404 may not engage in a handshake, andtherefore, may receive the set of subframes 410 without transmitting theacknowledgment 408.

FIG. 10 is a flowchart 1000 of a method of wireless communication. Themethod may be performed by a UE (e.g., the UE 504). At 1002, the UE mayreceive from a base station a subframe associated with a numerologyconfiguration. The numerology configuration may be associated with afirst tone spacing in the subframe for a control channel and a secondtone spacing in the subframe for a data channel. For example, referringto FIG. 5, the UE may be the UE 504. The UE 504 may receive from thebase station 502 the subframe 506 having a numerology configurationdifferent numerologies for data and control channels.

At 1004, the UE may decode the received subframe based on the numerologyconfiguration. For example, referring to FIG. 5, the UE 504 may decodethe subframe 506 based on the numerology configuration. The UE 504 maydecode the subframe 506 by determining the first and second tonespacings associated with the numerology configuration based on areceived fallback subframe and by extracting the control informationand/or data from the subframe 506 based on the first and second tonespacings.

FIG. 11 is a conceptual data flow diagram 1100 illustrating the dataflow between different means/components in an exemplary apparatus 1102.The apparatus may be a base station (e.g., the base station 402 or thebase station 502) or a UE (e.g., the UE 404 or the UE 504). Theapparatus includes a reception component 1104, a numerology component1106, a fallback component 1108, and a transmission component 1110. Inone configuration, the numerology component 1106 may be configured todetermine a numerology configuration to be used for communicating with aUE 1150. The fallback component 1108 may be configured to determine oneor more fallback subframes. The reception component 1104 and/or thetransmission component 1110 may be configured to communicate with the UE1150 within the one or more fallback subframes based on the determinednumerology configuration. In one instance, the transmission component1110 may be further configured to transmit one or more signals toindicate, to the UE 1150, a second numerology configuration to be usedfor future communications with the UE 1150. In an aspect, thetransmission of the one or more signals may take place within a subsetof the one or more fallback subframes. In another instance, thetransmission component 1110 may be configured to transmit an activationcommand indicating when the second numerology configuration is to takeeffect, the reception component 1104 may be configured to receive anacknowledgment from the UE 1150 based on the transmitted activationcommand, and the transmission component 1110 may be configured totransmit to the UE 1150 a set of subframes with the second numerologyconfiguration after receiving the acknowledgment from the UE 1150. In anaspect, the transmission of the one or more signals may indicate atleast one of a third numerology configuration to be used in a futuresubframe or may indicate a fourth numerology configuration to be used ina future fallback subframe. In another aspect, the transmission of theone or more signals may indicate a tone spacing for a symbol on which acontrol channel is to be transmitted in a future subframe. In anotheraspect, the one or more fallback subframes may be UE-specific, common toall UEs associated with the base station, or common to a subset of UEsassociated with the base station. In another aspect, informationassociated with the one or more fallback subframes may be signaled in aMIB, a SIB, or in RRC signaling. In another aspect, the timing of whenthe one or more fallback subframes is to be transmitted may bepre-configured. In another aspect, the determined numerologyconfiguration may be UE-specific, common to all UEs associated with thebase station, or common to a subset of UEs associated with the basestation. In another aspect, the determined numerology configuration maybe signaled in a MIB, a SIB, or in RRC signaling. In another aspect, thedetermined numerology configuration may be pre-configured. In anotheraspect, the determined numerology configuration may be fixed, semipersistent or change dynamically.

In another configuration, the numerology component 1106 may beconfigured to determine a numerology configuration to be used for asubframe. The numerology configuration may include a first tone spacingin the subframe for a first set of symbols and a second tone spacing inthe subframe for a second set of symbols. The reception component 1104and/or the transmission component 1110 may be configured to communicatewith a second wireless device (e.g., a base station or a UE) within thesubframe based on the determined numerology configuration. In an aspect,the numerology configuration may be based on a nominal numerology. Inanother aspect, the subframe may include one or more gap symbols locatedbetween the first set of symbols (e.g., one or more symbols) and thesecond set of symbols (e.g., one or more symbols) in the subframe. Inanother aspect, the first set of symbols may be associated with acontrol channel and the second set of symbols may be associated with adata channel. In another aspect, the one or more gap symbols may belocated between the control channel and the data channel, and thecontrol channel and the data channel may have different frequencybandwidths. In another aspect, the first set of symbols in the subframemay be allocated for downlink transmission and the second set of symbolsin the subframe may be allocated for uplink transmission. In anotheraspect, the first set of symbols in the subframe may be allocated fordownlink control information and the second set of symbols in thesubframe may be allocated for downlink data, or the first set of symbolsin the subframe may be allocated for uplink control information and thesecond set of symbols in the subframe may be allocated for uplink data.In another aspect, the first set of symbols may be associated with afirst data channel and the second set of symbols may be associated witha second data channel. In another aspect, the first data channel in thesubframe may be a channel allocated for URLLC and the second datachannel may be a channel allocated for eMBB communications. In anotheraspect, the first set of symbols may be associated with a first controlchannel and the second set of symbols may be associated with a secondcontrol channel. In another aspect, the one or more gap symbols may benull (e.g., have no data) or include reference signals or L1 controlsignals. In another aspect, the one or more gap symbols may have a sametone spacing as the first set of symbols or have a different tonespacing from the first set of symbols. In another aspect, the one ormore gap symbols may enable the apparatus and/or the second wirelessdevice to switch between a transmit mode and a receive mode or mayenable the apparatus and/or the second wireless device to perform beamswitching during beam training. In another aspect, the first tonespacing may be the same as the second tone spacing, or the first tonespacing may be different from the second tone spacing. In anotheraspect, the first tone spacing may be an integer multiple of the secondtone spacing. In another aspect, the first tone spacing may be a firstinteger multiple of a tone spacing of a nominal numerology and thesecond tone spacing may be a second integer multiple of the tone spacingof the nominal numerology. In another instance, the numerology component1106 may be configured to determine whether to TDM the first set ofsymbols with the second set of symbols into adjacent locations withinthe subframe based on the determined numerology configuration of thesubframe. In an aspect, the numerology component 1106 may determine notto TDM the first set of symbols with the second set of symbols intoadjacent locations if the first set of symbols and the second set ofsymbols have different tone spacings and the transmission of the firstand the second sets of symbols on the adjacent locations will overlapwith symbol boundaries corresponding to a nominal numerology.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowcharts of FIGS. 7 and8. As such, each block in the aforementioned flowcharts of FIGS. 7 and 8may be performed by a component and the apparatus may include one ormore of those components. The components may be one or more hardwarecomponents specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

FIG. 12 is a diagram 1200 illustrating an example of a hardwareimplementation for an apparatus 1102′ employing a processing system1214. The processing system 1214 may be implemented with a busarchitecture, represented generally by the bus 1224. The bus 1224 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1214 and the overalldesign constraints. The bus 1224 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 1204, the components 1104, 1106, 1108, 1110, and thecomputer-readable medium/memory 1206. The bus 1224 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore, will not be described any further.

The processing system 1214 may be coupled to a transceiver 1210. Thetransceiver 1210 is coupled to one or more antennas 1220. Thetransceiver 1210 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1210 receives asignal from the one or more antennas 1220, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1214, specifically the reception component 1104. Inaddition, the transceiver 1210 receives information from the processingsystem 1214, specifically the transmission component 1110, and based onthe received information, generates a signal to be applied to the one ormore antennas 1220. The processing system 1214 includes a processor 1204coupled to a computer-readable medium/memory 1206. The processor 1204 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 1206. The software, whenexecuted by the processor 1204, causes the processing system 1214 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 1206 may also be used forstoring data that is manipulated by the processor 1204 when executingsoftware. The processing system 1214 further includes at least one ofthe components 1104, 1106, 1108, 1110. The components may be softwarecomponents running in the processor 1204, resident/stored in thecomputer readable medium/memory 1206, one or more hardware componentscoupled to the processor 1204, or some combination thereof. In oneconfiguration, the processing system 1214 may be a component of the eNB310 and may include the memory 376 and/or at least one of the TXprocessor 316, the RX processor 370, and the controller/processor 375.In another configuration, the processing system 1214 may be a componentof the UE 350 and may include the memory 360 and/or at least one of theTX processor 368, the RX processor 356, and the controller/processor359.

In one configuration, the apparatus 1102/1102′ for wirelesscommunication includes means for determining a numerology configurationto be used for communicating with a UE. The apparatus includes means fordetermining one or more fallback subframes. The apparatus includes meansfor communicating with the UE within the one or more fallback subframesbased on the determined numerology configuration. In one instance, theapparatus may include means for transmitting one or more signals toindicate, to the UE, a second numerology configuration to be used forfuture communications with the UE. In an aspect, the transmission of theone or more signals may take place within a subset of the one or morefallback subframes. In another instance, the apparatus may include meansfor transmitting an activation command indicating when the secondnumerology configuration is to take effect, means for receiving anacknowledgment from the UE based on the transmitted activation command,and means for transmitting to the UE a set of subframes with the secondnumerology configuration after receiving the acknowledgment from the UE.In an aspect, the transmission of the one or more signals may indicateat least one of a third numerology configuration to be used in a futuresubframe or may indicate a fourth numerology configuration to be used ina future fallback subframe. In another aspect, the transmission of theone or more signals may indicate a tone spacing for a symbol on which acontrol channel is to be transmitted in a future subframe. In anotheraspect, the one or more fallback subframes may be UE-specific, common toall UEs associated with the base station, or common to a subset of UEsassociated with the base station. In another aspect, informationassociated with the one or more fallback subframes may be signaled in aMIB, a SIB, or in RRC signaling. In another aspect, the timing of whenthe one or more fallback subframes is to be transmitted may bepre-configured. In another aspect, the determined numerologyconfiguration may be UE-specific, common to all UEs associated with thebase station, or common to a subset of UEs associated with the basestation. In another aspect, the determined numerology configuration maybe signaled in a MIB, a SIB, or in RRC signaling. In another aspect, thedetermined numerology configuration may be pre-configured. In anotheraspect, the determined numerology configuration may be fixed, semipersistent or change dynamically.

In another configuration, the apparatus 1102/1102′ for wirelesscommunication includes means for determining a numerology configurationto be used for a subframe. The numerology configuration may include afirst tone spacing in the subframe for a first set of symbols and asecond tone spacing in the subframe for a second set of symbols. Theapparatus includes means for communicating with a second wireless device(e.g., a base station or a UE) within the subframe based on thedetermined numerology configuration. In an aspect, the numerologyconfiguration may be based on a nominal numerology. In another aspect,the subframe may include one or more gap symbols located between thefirst set of symbols (e.g., one or more symbols) and the second set ofsymbols (e.g., one or more symbols) in the subframe. In another aspect,the first set of symbols may be associated with a control channel andthe second set of symbols may be associated with a data channel. Inanother aspect, the one or more gap symbols may be located between thecontrol channel and the data channel, and the control channel and thedata channel may have different frequency bandwidths. In another aspect,the first set of symbols in the subframe may be allocated for downlinktransmission and the second set of symbols in the subframe may beallocated for uplink transmission. In another aspect, the first set ofsymbols in the subframe may be allocated for downlink controlinformation and the second set of symbols in the subframe may beallocated for downlink data, or the first set of symbols in the subframemay be allocated for uplink control information and the second set ofsymbols in the subframe may be allocated for uplink data. In anotheraspect, the first set of symbols may be associated with a first datachannel and the second set of symbols may be associated with a seconddata channel. In another aspect, the first data channel in the subframemay be a channel allocated for URLLC and the second data channel may bea channel allocated for eMBB communications. In another aspect, thefirst set of symbols may be associated with a first control channel andthe second set of symbols may be associated with a second controlchannel. In another aspect, the one or more gap symbols may be null(e.g., have no data) or include reference signals or L1 control signals.In another aspect, the one or more gap symbols may have a same tonespacing as the first set of symbols or have a different tone spacingfrom the first set of symbols. In another aspect, the one or more gapsymbols may enable the apparatus and/or the second wireless device toswitch between a transmit mode and a receive mode or may enable theapparatus and/or the second wireless device to perform beam switchingduring beam training. In another aspect, the first tone spacing may bethe same as the second tone spacing, or the first tone spacing may bedifferent from the second tone spacing. In another aspect, the firsttone spacing may be an integer multiple of the second tone spacing. Inanother aspect, the first tone spacing may be a first integer multipleof a tone spacing of a nominal numerology and the second tone spacingmay be a second integer multiple of the tone spacing of the nominalnumerology. In another instance, apparatus may include means fordetermining whether to TDM the first set of symbols with the second setof symbols into adjacent locations within the subframe based on thedetermined numerology configuration of the subframe. In an aspect, themeans for determining whether to TDM may determine not to TDM the firstset of symbols with the second set of symbols into adjacent locations ifthe first set of symbols and the second set of symbols have differenttone spacings and the transmission of the first and the second sets ofsymbols on the adjacent locations will overlap with symbol boundariescorresponding to a nominal numerology.

The aforementioned means may be one or more of the aforementionedcomponents of the apparatus 1102 and/or the processing system 1214 ofthe apparatus 1102′ configured to perform the functions recited by theaforementioned means. As described supra, in one configuration, theprocessing system 1214 may include the TX Processor 316, the RXProcessor 370, and the controller/processor 375. As such, in oneconfiguration, the aforementioned means may be the TX Processor 316, theRX Processor 370, and the controller/processor 375 configured to performthe functions recited by the aforementioned means. In anotherconfiguration, the processing system 1214 may include the TX Processor368, the RX Processor 356, and the controller/processor 359. As such, inone configuration, the aforementioned means may be the TX Processor 368,the RX Processor 356, and the controller/processor 359 configured toperform the functions recited by the aforementioned means.

FIG. 13 is a conceptual data flow diagram 1300 illustrating the dataflow between different means/components in an exemplary apparatus 1302.The apparatus may be a UE (e.g., the UE 404 or the UE 504). Theapparatus includes a reception component 1304, a numerology component1306, a decoding component 1308, and a transmission component 1310. Inone configuration, the numerology component 1306 may be configured todetermine one or more fallback subframes and to determine a numerologyconfiguration to be used for communicating with a base station 1350within the one or more fallback subframes. The reception component 1304and/or the transmission component 1310 may be configured to communicatewith the base station 1350 within one or more fallback subframes basedon the determined numerology configuration. In one instance, thereception component 1304 may be configured to receive one or moresignals from the base station 1350 indicating a second numerologyconfiguration to be used for future communications with the base station1350. In an aspect, the reception of the one or more signals may takeplace within a subset of the one or more fallback subframes. In anotheraspect, the one or more signals may indicate at least one of a thirdnumerology configuration to be used in a future subframe or indicates afourth numerology configuration to be used in a future fallbacksubframe. In another aspect, the one or more signals may indicate a tonespacing for a symbol on which a control channel is to be transmitted ina future subframe. In another instance, the reception component 1304 maybe configured to receive an activation command indicating when thesecond numerology configuration is to take effect. In this instance, thetransmission component 1310 may be configured to transmit anacknowledgment to the base station 1350 based on the received activationcommand. The reception component 1304 may be configured to receive a setof subframes with the second numerology configuration after transmittingthe acknowledgment. In an aspect, the one or more fallback subframes maybe UE-specific, common to all UEs associated with the base station, orcommon to a subset of UEs associated with the base station 1350. Inanother aspect, information associated with the one or more fallbacksubframes may be signaled in a MIB, a SIB, or in RRC signaling. Inanother aspect, the one or more fallback subframes may bepre-configured. In another aspect, the numerology configuration may beUE-specific, common to all UEs associated with the base station, orcommon to a subset of UEs associated with the base station 1350. Inanother aspect, the numerology configuration may be signaled in a MIB, aSIB, or in RRC signaling. In another aspect, the numerologyconfiguration may be pre-configured. In another aspect, the numerologyconfiguration may be fixed, semi persistent (e.g., remains the same fora predetermined number of subframes) or changes dynamically.

In another configuration, the reception component 1304 may be configuredto receive from the base station 1350 a subframe associated with anumerology configuration. The numerology configuration may be associatedwith a first tone spacing in the subframe for a control channel and asecond tone spacing in the subframe for a data channel. The decodingcomponent 1308 may be configured to decode the received subframe basedon the numerology configuration. In an aspect, the first tone spacingmay be the same as the second tone spacing. In another aspect, the firsttone spacing may be different from the second tone spacing. In anotheraspect, the first tone spacing may be an integer multiple of the secondtone spacing. In another aspect, the first tone spacing may be a firstinteger multiple of a tone spacing of a nominal numerology and thesecond tone spacing may be a second integer multiple of the tone spacingof a nominal numerology. In another aspect, the subframe may include oneor more gap symbols between the transmission of the control channel andthe data channel. In another aspect, the one or more gap symbols mayinclude reference signals or L1 control signals. In another aspect, theone or more gap symbols may use a same tone spacing as the controlchannel or may use a different tone spacing from the control channel. Inanother aspect, a first tone spacing of the control channel may be aninteger multiple of a second tone spacing of the data channel, and theone or more gap symbols may have the first tone spacing.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned flowcharts of FIGS. 9 and10. As such, each block in the aforementioned flowcharts of FIGS. 9 and10 may be performed by a component and the apparatus may include one ormore of those components. The components may be one or more hardwarecomponents specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

FIG. 14 is a diagram 1400 illustrating an example of a hardwareimplementation for an apparatus 1402′ employing a processing system1414. The processing system 1414 may be implemented with a busarchitecture, represented generally by the bus 1424. The bus 1424 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1414 and the overalldesign constraints. The bus 1424 links together various circuitsincluding one or more processors and/or hardware components, representedby the processor 1404, the components 1304, 1306, 1308, 1310, and thecomputer-readable medium/memory 1406. The bus 1424 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore, will not be described any further.

The processing system 1414 may be coupled to a transceiver 1410. Thetransceiver 1410 is coupled to one or more antennas 1420. Thetransceiver 1410 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1410 receives asignal from the one or more antennas 1420, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1414, specifically the reception component 1304. Inaddition, the transceiver 1410 receives information from the processingsystem 1414, specifically the transmission component 1310, and based onthe received information, generates a signal to be applied to the one ormore antennas 1420. The processing system 1414 includes a processor 1404coupled to a computer-readable medium/memory 1406. The processor 1404 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 1406. The software, whenexecuted by the processor 1404, causes the processing system 1414 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 1406 may also be used forstoring data that is manipulated by the processor 1404 when executingsoftware. The processing system 1414 further includes at least one ofthe components 1304, 1306, 1308, 1310. The components may be softwarecomponents running in the processor 1404, resident/stored in thecomputer readable medium/memory 1406, one or more hardware componentscoupled to the processor 1404, or some combination thereof. Theprocessing system 1414 may be a component of the UE 350 and may includethe memory 360 and/or at least one of the TX processor 368, the RXprocessor 356, and the controller/processor 359.

In one configuration, the apparatus 1302/1302′ for wirelesscommunication includes means for determining one or more fallbacksubframes and to determine a numerology configuration to be used forcommunicating with a base station within the one or more fallbacksubframes. The apparatus includes means for communicating with the basestation within one or more fallback subframes based on the determinednumerology configuration. In one instance, the apparatus may includemeans for receiving one or more signals from the base station indicatinga second numerology configuration to be used for future communicationswith the base station. In an aspect, the reception of the one or moresignals may take place within a subset of the one or more fallbacksubframes. In another aspect, the one or more signals may indicate atleast one of a third numerology configuration to be used in a futuresubframe or indicates a fourth numerology configuration to be used in afuture fallback subframe. In another aspect, the one or more signals mayindicate a tone spacing for a symbol on which a control channel is to betransmitted in a future subframe. In another instance, the apparatus mayinclude means for receiving an activation command indicating when thesecond numerology configuration is to take effect. In this instance, theapparatus may include means for transmitting an acknowledgment to thebase station based on the received activation command. The apparatus mayinclude means for receiving a set of subframes with the secondnumerology configuration after transmitting the acknowledgment. In anaspect, the one or more fallback subframes may be UE-specific, common toall UEs associated with the base station, or common to a subset of UEsassociated with the base station. In another aspect, informationassociated with the one or more fallback subframes may be signaled in aMIB, a SIB, or in RRC signaling. In another aspect, the one or morefallback subframes may be pre-configured. In another aspect, thenumerology configuration may be UE-specific, common to all UEsassociated with the base station, or common to a subset of UEsassociated with the base station. In another aspect, the numerologyconfiguration may be signaled in a MIB, a SIB, or in RRC signaling. Inanother aspect, the numerology configuration may be pre-configured. Inanother aspect, the numerology configuration may be fixed, semipersistent (e.g., remains the same for a predetermined number ofsubframes) or changes dynamically.

In one configuration, the apparatus 1302/1302′ for wirelesscommunication includes means for receiving from the base station asubframe associated with a numerology configuration. The numerologyconfiguration may be associated with a first tone spacing in thesubframe for a control channel and a second tone spacing in the subframefor a data channel. The apparatus includes means for decoding thereceived subframe based on the numerology configuration. In an aspect,the first tone spacing may be the same as the second tone spacing. Inanother aspect, the first tone spacing may be different from the secondtone spacing. In another aspect, the first tone spacing may be aninteger multiple of the second tone spacing. In another aspect, thefirst tone spacing may be a first integer multiple of a tone spacing ofa nominal numerology and the second tone spacing may be a second integermultiple of the tone spacing of a nominal numerology. In another aspect,the subframe may include one or more gap symbols between thetransmission of the control channel and the data channel. In anotheraspect, the one or more gap symbols may include reference signals or L1control signals. In another aspect, the one or more gap symbols may usea same tone spacing as the control channel or may use a different tonespacing from the control channel. In another aspect, a first tonespacing of the control channel may be an integer multiple of a secondtone spacing of the data channel, and the one or more gap symbols mayhave the first tone spacing.

The aforementioned means may be one or more of the aforementionedcomponents of the apparatus 1302 and/or the processing system 1414 ofthe apparatus 1302′ configured to perform the functions recited by theaforementioned means. As described supra, the processing system 1414 mayinclude the TX Processor 368, the RX Processor 356, and thecontroller/processor 359. As such, in one configuration, theaforementioned means may be the TX Processor 368, the RX Processor 356,and the controller/processor 359 configured to perform the functionsrecited by the aforementioned means.

It is understood that the specific order or hierarchy of blocks in theprocesses / flowcharts disclosed is an illustration of exemplaryapproaches. Based upon design preferences, it is understood that thespecific order or hierarchy of blocks in the processes/flowcharts may berearranged. Further, some blocks may be combined or omitted. Theaccompanying method claims present elements of the various blocks in asample order, and are not meant to be limited to the specific order orhierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects. Unless specifically statedotherwise, the term “some” refers to one or more. Combinations such as“at least one of A, B, or C,” “one or more of A, B, or C,” “at least oneof A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or anycombination thereof” include any combination of A, B, and/or C, and mayinclude multiples of A, multiples of B, or multiples of C. Specifically,combinations such as “at least one of A, B, or C,” “one or more of A, B,or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and“A, B, C, or any combination thereof” may be A only, B only, C only, Aand B, A and C, B and C, or A and B and C, where any such combinationsmay contain one or more member or members of A, B, or C. All structuraland functional equivalents to the elements of the various aspectsdescribed throughout this disclosure that are known or later come to beknown to those of ordinary skill in the art are expressly incorporatedherein by reference and are intended to be encompassed by the claims.Moreover, nothing disclosed herein is intended to be dedicated to thepublic regardless of whether such disclosure is explicitly recited inthe claims. The words “module,” “mechanism,” “element,” “device,” andthe like may not be a substitute for the word “means.” As such, no claimelement is to be construed as a means plus function unless the elementis expressly recited using the phrase “means for.”

What is claimed is:
 1. A method of wireless communication by a firstwireless device, comprising: determining a numerology configuration tobe used for a subframe, the numerology configuration comprising a firsttone spacing in the subframe for a first set of symbols and a secondtone spacing in the subframe for a second set of symbols; andcommunicating with a second wireless device within the subframe based onthe determined numerology configuration.
 2. The method of claim 1,wherein the numerology configuration is based on a nominal numerology.3. The method of claim 1, wherein the subframe comprises one or more gapsymbols located between the first set of symbols and the second set ofsymbols in the subframe.
 4. The method of claim 3, wherein the first setof symbols is associated with a control channel and the second set ofsymbols is associated with a data channel.
 5. The method of claim 4,wherein the one or more gap symbols are located between the controlchannel and the data channel, and the control channel and the datachannel have different frequency bandwidths.
 6. The method of claim 3,wherein the first set of symbols in the subframe is allocated fordownlink transmission and the second set of symbols in the subframe isallocated for uplink transmission.
 7. The method of claim 3, wherein thefirst set of symbols in the subframe is allocated for downlink controlinformation and the second set of symbols in the subframe is allocatedfor downlink data, or wherein the first set of symbols in the subframeis allocated for uplink control information and the second set ofsymbols in the subframe is allocated for uplink data.
 8. The method ofclaim 3, wherein the first set of symbols is associated with a firstdata channel and the second set of symbols is associated with a seconddata channel.
 9. The method of claim 8, wherein the first data channelin the subframe comprises ultra-reliable and low-latency communications(URLLC) and the second data channel comprises enhanced mobile broadband(eMBB) communications.
 10. The method of claim 3, wherein the first setof symbols is associated with a first control channel and the second setof symbols is associated with a second control channel.
 11. The methodof claim 3, wherein the one or more gap symbols are null or comprisereference signals or L1 control signals.
 12. The method of claim 11,wherein the one or more gap symbols use a same tone spacing as the firstset of symbols or uses a different tone spacing from the first set ofsymbols.
 13. The method of claim 3, wherein the one or more gap symbolsenables at least one of the first wireless device or the second wirelessdevice to switch between a transmit mode and a receive mode or enablesthe at least one of the first wireless device or the second wirelessdevice to perform beam switching during beam training.
 14. The method ofclaim 1, wherein the first tone spacing is the same as the second tonespacing, or wherein the first tone spacing is different from the secondtone spacing.
 15. The method of claim 14, wherein the first tone spacingis an integer multiple of the second tone spacing.
 16. The method ofclaim 14, wherein the first tone spacing is a first integer multiple ofa tone spacing of a nominal numerology and the second tone spacing is asecond integer multiple of the tone spacing of the nominal numerology.17. The method of claim 1, further comprising determining whether totime-division multiplex (TDM) the first set of symbols with the secondset of symbols into adjacent locations within the subframe based on thedetermined numerology configuration of the subframe.
 18. The method ofclaim 17, wherein the first wireless device determines not to TDM thefirst set of symbols with the second set of symbols into adjacentlocations if the first set of symbols and the second set of symbols havedifferent tone spacings and the transmission of the first and the secondsets of symbols on the adjacent locations will overlap with symbolboundaries corresponding to a nominal numerology.
 19. A first wirelessdevice for wireless communication, comprising: a memory; and at leastone processor coupled to the memory and configured to: determine anumerology configuration to be used for a subframe, the numerologyconfiguration comprising a first tone spacing in the subframe for afirst set of symbols and a second tone spacing in the subframe for asecond set of symbols; and communicate with a second wireless devicewithin the subframe based on the determined numerology configuration.20. The first wireless device of claim 19, wherein the subframecomprises one or more gap symbols located between the first set ofsymbols and the second set of symbols in the subframe.
 21. The firstwireless device of claim 20, wherein the first set of symbols isassociated with a control channel and the second set of symbols isassociated with a data channel, and wherein the one or more gap symbolsare located between the control channel and the data channel, and thecontrol channel and the data channel have different frequencybandwidths.
 22. The first wireless device of claim 20, wherein the firstset of symbols in the subframe is allocated for downlink controlinformation and the second set of symbols in the subframe is allocatedfor downlink data, or wherein the first set of symbols in the subframeis allocated for uplink control information and the second set ofsymbols in the subframe is allocated for uplink data.
 23. The firstwireless device of claim 20, wherein the one or more gap symbols enablesat least one of the first wireless device or the second wireless deviceto switch between a transmit mode and a receive mode or enables the atleast one of the first wireless device or the second wireless device toperform beam switching during beam training.
 24. The first wirelessdevice of claim 19, wherein the first tone spacing is the same as thesecond tone spacing, or wherein the first tone spacing is different fromthe second tone spacing.
 25. The first wireless device of claim 24,wherein the first tone spacing is an integer multiple of the second tonespacing.
 26. The first wireless device of claim 24, wherein the firsttone spacing is a first integer multiple of a tone spacing of a nominalnumerology and the second tone spacing is a second integer multiple ofthe tone spacing of the nominal numerology.
 27. The first wirelessdevice of claim 19, wherein the at least one processor is furtherconfigured to determine whether to time-division multiplex (TDM) thefirst set of symbols with the second set of symbols into adjacentlocations within the subframe based on the determined numerologyconfiguration of the subframe.
 28. The first wireless device of claim27, wherein the first wireless device determines not to TDM the firstset of symbols with the second set of symbols into adjacent locations ifthe first set of symbols and the second set of symbols have differenttone spacings and the transmission of the first and the second sets ofsymbols on the adjacent locations will overlap with symbol boundariescorresponding to a nominal numerology.
 29. A first wireless device forwireless communication, comprising: means for determining a numerologyconfiguration to be used for a subframe, the numerology configurationcomprising a first tone spacing in the subframe for a first set ofsymbols and a second tone spacing in the subframe for a second set ofsymbols; and means for communicating with a second wireless devicewithin the subframe based on the determined numerology configuration.30. A computer-readable medium of a first wireless device storingcomputer executable code, comprising code to: determine a numerologyconfiguration to be used for a subframe, the numerology configurationcomprising a first tone spacing in the subframe for a first set ofsymbols and a second tone spacing in the subframe for a second set ofsymbols; and communicate with a second wireless device within thesubframe based on the determined numerology configuration.